Unity-Technologies/UnityCsReference · error · ArgumentException

Scripting backend value {scriptingBackend} is not supported.

Error message

Scripting backend value {scriptingBackend} is not supported.

What it means

Thrown by GetNiceScriptingBackendName when a ScriptingImplementation value is not Mono2x, IL2CPP, or CoreCLR. The switch is meant to be exhaustive over the supported scripting backends; any other value is unsupported.

Source

Thrown at Editor/Mono/Inspector/PlayerSettingsEditor/PlayerSettingsEditor.cs:4742

        }

        static GUIContent[] GetNiceScriptingBackendNames(ScriptingImplementation[] scriptingBackends)
        {
            return Array.ConvertAll(scriptingBackends, s => GetNiceScriptingBackendName(s));
        }

        static GUIContent GetNiceScriptingBackendName(ScriptingImplementation scriptingBackend)
        {
            switch (scriptingBackend)
            {
                case ScriptingImplementation.Mono2x:
                    return SettingsContent.scriptingMono2x;
                case ScriptingImplementation.IL2CPP:
                    return SettingsContent.scriptingIL2CPP;
                case ScriptingImplementation.CoreCLR:
                    return SettingsContent.scriptingCoreCLR;
                default:
                    throw new ArgumentException($"Scripting backend value {scriptingBackend} is not supported.", nameof(scriptingBackend));
            }
        }

        private static GUIContent[] GetNiceApiCompatibilityLevelNames(ApiCompatibilityLevel[] apiCompatibilityLevels)
        {
            if (m_NiceApiCompatibilityLevelNames == null)
            {
                m_NiceApiCompatibilityLevelNames = new Dictionary<ApiCompatibilityLevel, GUIContent>
                {
                    { ApiCompatibilityLevel.NET_Unity_4_8, SettingsContent.apiCompatibilityLevel_NET_FW_Unity },
                    { ApiCompatibilityLevel.NET_Standard, SettingsContent.apiCompatibilityLevel_NET_Standard },
                    // ApiCompatibilityLevel.NET is intentionally Obsolete/hidden for now, but still needs a display name here.
#pragma warning disable 618
                    { ApiCompatibilityLevel.NET, SettingsContent.apiCompatibilityLevel_NET_10 },
#pragma warning restore 618
                };
            }

View on GitHub (pinned to 225b0fbdb5)

Solutions

1. Ensure the ScriptingImplementation is one of Mono2x, IL2CPP, or CoreCLR for the active editor build.
2. Install the platform backend module if a required backend is missing.
3. Guard before calling: validate against the supported set and use a default.

Example fix

// before
var name = GetNiceScriptingBackendName(backend);

// after
var supported = backend == ScriptingImplementation.Mono2x
              || backend == ScriptingImplementation.IL2CPP
              || backend == ScriptingImplementation.CoreCLR;
if (!supported) { Debug.LogWarning($"Unsupported backend {backend}"); backend = ScriptingImplementation.IL2CPP; }
var name = GetNiceScriptingBackendName(backend);

bool IsSupportedBackend(ScriptingImplementation b) =>
    b == ScriptingImplementation.Mono2x || b == ScriptingImplementation.IL2CPP || b == ScriptingImplementation.CoreCLR;

static bool IsSupportedBackend(ScriptingImplementation b) =>
    b == ScriptingImplementation.Mono2x || b == ScriptingImplementation.IL2CPP || b == ScriptingImplementation.CoreCLR;

When it happens

Trigger: Calling GetNiceScriptingBackendName with a ScriptingImplementation that is not currently supported (e.g. a disabled/preview backend). A build profile or platform exposing a backend the editor build does not include.

Common situations: Platform-specific scripting backends not installed. Enum values from a newer Unity version rendered by an older editor. Custom player settings scripting that sets an unsupported backend.

Related errors

• Missing name for {0}
• Unhandled scripting backend {scriptingBackend}
• Attempting to set an incorrect number of icons for {namedBui
• The setting label can't be null or empty.
• Unknown scripting backend:{scriptingBackend}

AI-assisted analysis of Unity-Technologies/UnityCsReference@225b0fbdb5 (2026-08-13). Data as JSON: /api/errors/d9f8b9ec872fd589. Report an issue: GitHub.